1. Field of the Invention
The present invention is directed to a radiological system of the type capable of generating a "normal" image corresponding to a standards system, as well as an "H-image" which has a higher number of lines that the normal image.
2. Description of the Prior Art
Radiological systems are known which can be operated in different modes, using different image processing chains, to produce a so-called "normal image" according to a standards system (such as the NTSC system in the United States, or different systems in Europe), as well as a so-called "H-image" which has a higher number of image lines than the normal image, in order to provide higher definition of a region of the examination subject.
Radiological systems of this type are installed in certain clinics. Typically, the image processing chain will include an N-output for the normal images, to which a video recorder is connectable, and an H-output for the H-image, to which an H-image playback unit is connectable. A video recorder as disclosed, for example, in U.S. Pat. No. 5,054,045 can only record normal images with a normal number of lines (for example, 625 lines) with good image quality. If an attempt were made to employ such a known video recorder to record an image having a high number of lines, for example 1249 lines, recording would, at most, be possible with very poor image quality. For this reason, known systems of the type described above employ a separate image playback unit for the normal images having a normal number of lines, connected to the output of the video recorder. At least one H-image playback unit for images having a higher number of lines is also connected to a separate output of the image processing chain in such known systems.
The video recorder, therefore, does not participate in the transmission chain for playback of the H-image.
An x-ray diagnostics installation is disclosed U.S. Pat. No. 5,022,063 which can be operated in a number of imaging modes. In a fluoroscopic mode, the video camera operates with a low, i.e., normal resolution. The output of the video camera is connected to a processing circuit which reproduces normal images with a normal number of lines. In a number of operating modes for registering x-ray images, the video camera can be operated at a higher frame rate, or with a higher number of lines per frame. The output of the video camera in these operating modes is connected to a separate circuit for processing and reproducing high-resolution images. Due to this double circuit outlay--two processing circuits, two analog-to-digital converters, two digital-to-analog converters, and two monitors per video channel and per observation station, this known radiological system is expensive and complicated.